Maria Kutar

Cognitive Dimensions of Notations: Design Tools for Cognitive Technology

The Cognitive Dimensions of Notations framework has been created to assist the designers of notational systems and information artifacts to evaluate their designs with respect to the impact that they will have on the users of those designs. The framework emphasizes the design choices available to such designers, including characterization of the users activity, and the inevitable tradeoffs that will occur between potential design options. The resuliing framework has been under development for over 10 years, and now has an active community of researchers devoted to it. This paper first introduces Cognitive Dimensions. It then summarizes the current activity, especially the results of a one-day workshop devoted to Cognitive Dimensions in December 2000, and reviews the ways in which it applies to the field of Cognitive Technology.

Specifying multiple time granularities in interactive systems

Time plays an important role in interactive systems, but can be difficult to specify, particularly where temporal properties exist at several different time granularities. The relationship between different time granularities is complex and translation between them can be difficult. In this paper, we discuss this relationship and highlight the way in which translation between different time granularities within a single specification may have important consequences for system behaviour. Using the notation TRIO≠, we provide examples from an interactive case study of the ways in which system behaviour may be influenced, and illustrate some of the potential difficulties which arise in the specification of temporal properties such as pace and regularity.

An empirical study of user preference and performance with UML diagrams

Elicitation and validation of user requirements depend, to a large extent, on the effectiveness of the tools and techniques used as a vehicle for discussion between developers and users during the requirements process. This effectiveness may, in turn, be influenced by user preference for a particular approach or requirements technique. This paper describes a study that was carried out to investigate the relationship between user preference for sequence or collaboration diagrams in UML, with their accuracy in understanding information contained in the diagrams. Results showed that user preference for one of the two diagram types before carrying out the task was not reflected in improved performance with that type of diagram compared with the other. However, after carrying out the task, user statements about which type of diagram they preferred working with were matched by improved performance with that type of diagram.

Evaluating the Intelligibility of Diagrammatic Languages Used in the Specification of Software

This paper presents an approach to evaluating the intelligibility of diagrammatic languages used in the specification of software. Research suggests that specification languages can be assessed in terms of properties that influence the intelligibility of representations produced using the languages. The paper describes the properties identified and highlights three in particular that have been shown to influence the intelligibility of representations: motivation of symbols in the language; the extent to which the language allows exploitation of human visual perception; and the amount of structure inherent in the language. The paper argues that the first two of these properties are not present to any great extent in diagrammatic languages used in software specification. In order to enhance the intelligibility of software specifications, we suggest that more attention should be paid to ways in which these languages can exploit the amount of structure inherent in the language.

The Cognitive Dimensions of an Artifact vis-à-vis Individual Human Users: Studies with Notations for the Temporal Specification of Interactive Systems

Cognitive Technology explores ways in which the cognitive fit between people and technology may be optimized. If this goal is to be achieved we will require methods of assessing tools and information arftifacts in order that we may properly examine the interplay between human cognition and technologies. Examination of this relationship neccessitates recogniton of the fact that it will be shaped by the cognitive and embodiment characteristics of the user, as well as the activity being carried out and the nature of the technology or artifact itself. The Cognitive Dimensions (CDs) framework provides a set of tools and measures which may contribute to Cognitive Technologys aims. CDs provide a pragmatic approach to the assessment of information artifacts, highlighting properties which affect cognition. We argue that not only may CDs be of benefit to Cognitive Technology, but that Cognitive Technology provides a broader context for understanding the importance and impact of CDs. Greater awareness of the importance of particular characteristics of users may serve to inform the application of CDs. In this paper we provide a general introduction to the CD framework, and show how CDs have been used in the evaluation and improvement of a temporal specification notation for interactive systems. We then discuss the ways in which user characteristics may be taken into account in applications of the CD framework. We illustrate the discussion with examples showing the differing impact of a temporal specification notations properties on experienced and novice users.